/*
 * LabeledMarker Class Copyright 2007 Mike Purvis (http://uwmike.com) Licensed
 * under the Apache License, Version 2.0 (the "License"); you may not use this
 * file except in compliance with the License. You may obtain a copy of the
 * License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
 * applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
 * OF ANY KIND, either express or implied. See the License for the specific
 * language governing permissions and limitations under the License. This class
 * extends the Maps API's standard GMarker class with the ability to support
 * markers with textual labels. Please see articles here:
 * http://googlemapsbook.com/2007/01/22/extending-gmarker/
 * http://googlemapsbook.com/2007/03/06/clickable-labeledmarker/
 */

/**
 * Constructor for LabeledMarker, which picks up on strings from the GMarker
 * options array, and then calls the GMarker constructor.
 * @param {GLatLng} latlng
 * @param {GMarkerOptions} Named optional arguments: opt_opts.labelText {String}
 *          text to place in the overlay div. opt_opts.labelClass {String} class
 *          to use for the overlay div. (default "markerLabel")
 *          opt_opts.labelOffset {GSize} label offset, the x- and y-distance
 *          between the marker's latlng and the upper-left corner of the text
 *          div.
 */
function LabeledMarker(latlng, opt_opts) {
  this.latlng_ = latlng;
  this.opts_ = opt_opts;

  this.initText_ = opt_opts.labelText || "";
  this.labelClass_ = opt_opts.labelClass || "markerLabel";
  this.labelOffset_ = opt_opts.labelOffset || new GSize(0, 0);

  this.clickable_ = opt_opts.clickable || true;

  GMarker.apply(this, arguments);
}

// It's a limitation of JavaScript inheritance that we can't conveniently
// inherit from GMarker without having to run its constructor. In order for
// the constructor to run, it requires some dummy GLatLng.
LabeledMarker.prototype = new GMarker(new GLatLng(0, 0));

/**
 * Is called by GMap2's addOverlay method. Creates the text div and adds it to
 * the relevant parent div.
 * @param {GMap2} map the map that has had this labeledmarker added to it.
 */
LabeledMarker.prototype.initialize = function(map) {
  // Do the GMarker constructor first.
  GMarker.prototype.initialize.apply(this, arguments);

  this.map_ = map;
  this.setText(this.initText_);
}

/**
 * Create a new div for this label.
 */
LabeledMarker.prototype.makeDiv_ = function(map) {
  if (this.div_) {
    return;
  }
  this.div_ = document.createElement("div");
  this.div_.className = this.labelClass_;
  this.div_.style.position = "absolute";
  this.div_.style.cursor = "pointer";
  this.map_.getPane(G_MAP_MARKER_PANE).appendChild(this.div_);

  if (this.clickable_) {
    /**
     * Creates a closure for passing events through to the source marker This is
     * located in here to avoid cluttering the global namespace. The downside is
     * that the local variables from initialize() continue to occupy space on
     * the stack.
     * @param {Object} object to receive event trigger.
     * @param {GEventListener} event to be triggered.
     */
    function newEventPassthru(obj, event) {
      return function() {
        GEvent.trigger(obj, event);
      };
    }

    // Pass through events fired on the text div to the marker.
    var eventPassthrus =
        ['click', 'dblclick', 'mousedown', 'mouseup', 'mouseover', 'mouseout'];
    for (var i = 0; i < eventPassthrus.length; i++) {
      var name = eventPassthrus[i];
      GEvent.addDomListener(this.div_, name, newEventPassthru(this, name));
    }
  }
}

/**
 * Return the html in the div of this label, or "" if none is set
 */
LabeledMarker.prototype.getText = function(text) {
  if (this.div_) {
    return this.div_.innerHTML;
  } else {
    return "";
  }
}

/**
 * Set the html in the div of this label to text. If text is "" or null remove
 * the div.
 */
LabeledMarker.prototype.setText = function(text) {
  if (this.div_) {
    if (text) {
      this.div_.innerHTML = text;
    } else {
      // remove div
      GEvent.clearInstanceListeners(this.div_);
      this.div_.parentNode.removeChild(this.div_);
      this.div_ = null;
    }
  } else {
    if (text) {
      this.makeDiv_();
      this.div_.innerHTML = text;
      this.redraw();
    }
  }
}

/**
 * Move the text div based on current projection and zoom level, call the
 * redraw() handler in GMarker.
 * @param {Boolean} force will be true when pixel coordinates need to be
 *          recomputed.
 */
LabeledMarker.prototype.redraw = function(force) {
  GMarker.prototype.redraw.apply(this, arguments);

  if (this.div_) {
    // Calculate the DIV coordinates of two opposite corners of our bounds to
    // get the size and position of our rectangle
    var p = this.map_.fromLatLngToDivPixel(this.getLatLng());
    var z = GOverlay.getZIndex(this.latlng_.lat());

    // Now position our div based on the div coordinates of our bounds
    this.div_.style.left = (p.x + this.labelOffset_.width) + "px";
    this.div_.style.top = (p.y + this.labelOffset_.height) + "px";
    this.div_.style.zIndex = z; // in front of the marker
  }
}

/**
 * Remove the text div from the map pane, destroy event passthrus, and calls the
 * default remove() handler in GMarker.
 */
LabeledMarker.prototype.remove = function() {
  this.setText(null);
  GMarker.prototype.remove.apply(this, arguments);
}

/**
 * Return a copy of this overlay, for the parent Map to duplicate itself in
 * full. This is part of the Overlay interface and is used, for example, to copy
 * everything in the main view into the mini-map.
 */
LabeledMarker.prototype.copy = function() {
  return new LabeledMarker(this.latlng_, this.opt_opts_);
}
